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Abstract:

A method is disclosed for mechanically deboning animal thighs for
separating and collecting meat therefrom and an apparatus (1) for
performing the method, including automated individual processing steps.
The processing steps include: grasping a thigh bone of an animal thigh at
a hip knuckle with a bone holder (17); cutting tissue near the hip
knuckle; and engaging the thigh bone adjacent the bone holder with a meat
stripper (165). The processing steps further include: moving the bone
holder (17) and meat stripper (165) away from one another in a direction
substantially coextensive with the longitudinal extent of the thigh bone;
allowing the meat stripper (165) to pass over the knee knuckle; and
collecting the meat separated from the bone. In particular the method
includes and the apparatus (1) performs the process step of cutting
tissue adjacent a knee knuckle of the thigh bone, prior to allowing the
meat stripper (165) to pass over the knee knuckle. The apparatus (1)
includes a plurality of processing stations (23, 25, 27, 29, 68, 77, 79,
81) for carrying out the individual steps, and the processing stations
are arranged along a path of conveyance defined by a conveyor chain (35,
41, 43) moving through a predefined path (3, 5, 7, 9).

Claims:

1. A method of deboning animal thighs for separating and collecting meat
therefrom, including automated individual processing steps, the method
comprising the steps of: grasping a thigh bone of an animal thigh at a
hip knuckle with a bone holder; cutting tissue near the hip knuckle;
engaging the thigh bone adjacent the bone holder with a meat stripper;
moving the bone holder and meat stripper away from one another in a
direction substantially coextensive with the longitudinal extent of the
thigh bone; cutting tissue adjacent a knee knuckle of the thigh bone;
allowing the meat stripper to pass over the knee knuckle to separate the
meat from the bone; and collecting the meat separated from the bone.

2. A method according to claim 1, wherein the step of cutting tissue
adjacent a knee knuckle of the thigh bone further includes supporting and
moving a portion of the thigh bone adjacent the knee knuckle while in
contact with a cutting blade.

3. A method according to claim 2, wherein the cutting blade comprises a
rotating cutting blade.

4. A method according to claim 1, wherein the step of cutting tissue near
the knee knuckle of the thigh bone precedes the step of cutting tissue
near the hip knuckle.

5. A method according to one of claims 1, wherein the step of cutting
tissue adjacent the knee knuckle of the thigh bone also includes keeping
a portion of the thigh bone adjacent the knee knuckle in engagement with
a non-rotating knife blade, while advancing the animal thigh through a
path of travel defined by the individual processing steps.

6. A method according to claim 4, wherein the keeping of the portion of
the thigh bone adjacent the knee knuckle in engagement with a
non-rotating knife blade is a further step following the step of claim 2,
and cuts knee knuckle related tissue that connects the meat to the bone
at a side portion of the bone shaft adjacent the knee knuckle
perpendicular to the tissue cut by the step of claim 2.

7. A method according to claim 6, wherein the cutting steps of claims 2
and claim 4, each include cutting from opposite sides of the bone shaft
adjacent the knee knuckle.

8. A method according to one of claims 1, further comprising advancing
the animal thigh along a processing path while performing the individual
processing steps.

9. A method according to one of claims 1, wherein the step of cutting
tissue near the hip knuckle includes rotating the bone holder about an
axis substantially coextensive with a longitudinal extent of the thigh
bone, while keeping a portion of the thigh bone adjacent the hip knuckle
in engagement with a knife edge.

10. A method according to claim 9, wherein the step of cutting tissue
near the hip knuckle includes passing the portion of the hip bone
adjacent to the hip knuckle between oppositely disposed knife edges that
are biased towards one another.

11. A method according to one of claims 1, further comprising collecting
meat for further processing after the meat stripper has passed over the
knee knuckle.

12. A method according to claim 11, further comprising releasing the
thigh bone after collecting the meat.

13. A method according to claim 1, wherein the steps are performed while
conveying the animal thighs along a conveying path that extends through a
closed loop.

14. An apparatus for performing the method of claim 1, comprising a
plurality of processing stations for carrying out the individual steps,
the processing stations being arranged along a path of conveyance defined
by a conveyor chain moving through a predefined path.

15. An apparatus according to claim 14, and wherein the conveyor chain is
arranged for moving the bone holder through the conveying path, while the
processing stations are activated to perform the individual processing
steps.

16. An apparatus according to claim 15, wherein the conveying path is
arranged in a closed loop and wherein the conveyor chain is endless and
extends through the closed loop.

17. An apparatus according to claim 16, wherein the closed loop is
defined by first and second carousels, connecting parallel first and
second linear conveyor sections.

18. An apparatus according to one of claims 14, wherein the bone holder
is adapted for rotation about an axis substantially coextensive with a
longitudinal extent of a thigh bone grasped thereby.

19. An apparatus according to claim 18, wherein the bone holder is
rotatably suspended from a conveyor chain shackle.

20. An apparatus according to claim 19, wherein the bone conveyor chain
shackle is adapted to be moved by the conveyor chain through the path of
conveyance.

21. An apparatus according to one of claims 18, wherein the bone holder
is adapted for selective rotation by one of a turning gear and a rotation
pinion.

22. An apparatus according to claim 21, wherein rotation of the bone
holder by the rotation pinion is selected for the processing step of
cutting tissue adjacent the hip knuckle at a hip knuckle tissue cutting
station.

23. An apparatus according to claim 22, wherein the hip knuckle tissue
cutting station includes a stationary toothed rack that is adapted to
engage the rotation pinion when the bone holder is moved along the path
of conveyance.

24. An apparatus according to claim 22, wherein the hip knuckle tissue
cutting station includes a pair of opposite cutting blades that are
resiliently biased toward a passage path along which the thigh bone is
conveyed.

25. An apparatus according to claim 21, wherein adjustment of the bone
holder from one to another of a number of discrete rotational positions
by the turning gear is selected when the bone holder passes each point
where the first linear conveyor section in the conveying path is
connecting with one of first and second carousels.

26. An apparatus according to one of claims 14, wherein the bone holder
comprises a swivelable locking arm.

27. An apparatus according to claim 26, wherein the swivelable locking
arm is resiliently biased to be in an open position and is adapted to be
swivelled to a closed position by engagement of the bone holder with a
cam track.

28. An apparatus according to claim 27, wherein the swivelable locking
arm is latched in its closed position when swivelled thereto.

29. An apparatus according to claim 17, wherein the meat stripper is
associated with the second carousel.

30. An apparatus according to claim 29, wherein the second carousel
defines a meat stripping and discharge section.

31. An apparatus according to claim 29, wherein the second carousel is
driven for rotation.

32. An apparatus according to claim 29, wherein the first carousel is
idle and driven indirectly by the conveyor chain.

33. An apparatus according to claim 32, wherein the first carrousel
defines a first tissue cutting section.

34. An apparatus according to one of claims 33, wherein the first of the
linear conveyor sections extends, in conveyance direction, from the
second carousel to the first carousel and defines a loading section.

35. An apparatus according to one of claims 34, wherein the second of the
linear conveyor sections extends, in direction of conveyance, from the
first carousel to the second carousel and defines a second tissue cutting
section.

36. A method of separating and collecting meat from animal thighs each
having a thigh bone with a hip knuckle at one end and a knee knuckle at
an opposite end, the method comprising the steps of: (a) gripping the hip
knuckle; (b) cutting tissue attaching the meat to the thigh bone at a
location adjacent the hip knuckle; (c) stripping meat from the thigh bone
in a direction extending from the hip knuckle toward the knee knuckle;
(d) cutting tissue attaching the meat to the thigh bone at a location
adjacent the knee knuckle; (e) urging the meat over the knee knuckle to
separate the meat substantially from the thigh bone; (f) collecting the
meat; and (g) discarding the bone.

37. An apparatus for separating and collecting meat from animal thighs
each having a thigh bone with a hip knuckle at one end and a knee knuckle
at an opposite end, the apparatus comprising: a conveyor defining and
movable along a processing path; a plurality of bone holders coupled to
the conveyor in spaced relationship and movable with the conveyor along
the processing path; each bone holder comprising a hip knuckle gripper
for gripping a thigh bone adjacent the hip knuckle thereof; a first
processing station disposed along the processing path and comprising at
least one cutting blade arranged to cut meat tissue attaching the meat to
the thigh bone at a designated location adjacent the hip knuckle as the
animal thigh is conveyed past the first processing station; a second
processing station disposed along the processing path and comprising at
least one cutting blade arranged to cut meat tissue attaching the meat to
the thigh bone at a designated location adjacent the knee knuckle as the
animal thigh is conveyed past the second processing station; a third
processing station disposed along the processing path and comprising a
meat stripper configured to engage and substantially surround the thigh
bone at a location between the hip knuckle gripper and the knee knuckle;
a mechanism for moving the meat stripper and the hip knuckle gripper away
from each other to strip the meat from the bone in a direction toward the
knee knuckle; the meat stripper moving over the knee knuckle to separate
the meat from the thigh bone; and a collection station for collecting the
meat separated from the thigh bone.

Description:

TECHNICAL FIELD

[0001] The invention relates generally to food processing and more
particularly to a method and apparatus for mechanically removing meat
from the encased thigh bones of animals such as poultry or fowl.

BACKGROUND

[0002] The ability to obtain large quantities of thigh meat from
slaughtered animals, such as poultry or fowl, by mechanical means is of
great importance to world food production. It is not uncommon in the food
industry, for instance, that well over a hundred thousand slaughtered
birds are processed in one day's shift at a poultry processing plant.

[0003] Various methods and apparatuses have been developed for removing
thigh meat from thigh bones or femurs of poultry and fowl as thighs are
moved along a processing path or cut-up line. Generally, cut-up lines for
bird carcasses can operate at high capacity, and suspend the carcasses by
their ankle joints from shackles. As a result, the legs legs and thighs
are commonly amongst the last items to be processed. This manner of
suspension and order of processing is not always ideal in getting the
best yield of meat and in preventing contamination of recovered meat by
bone fragments. It has therefore become increasingly popular to process
thigh meat separately from the traditional cut-up lines, at the
disadvantage of having to collect the yet unprocessed thighs and convey
and feed these one by one to a dedicated processing device. Part of this
drawback has been overcome in that one or a plurality of such thigh
processing devices can be operated simultaneous with an associated a
cut-up line. Such dedicated thigh deboning devices, as disclosed for
example in U.S. Pat. No. 3,510,908, often rely on manual labour, can be
cumbersome to operate, and do little if anything to increase processing
speed.

[0004] Accordingly, there is a need for an improved method and apparatus
for deboning animal thighs for separating and collecting meat from the
thigh bone. In a more general sense there is a need to overcome or
ameliorate at least one of the disadvantages of the prior art. There is
an overall need to provide alternative structures that are less
cumbersome in assembly and operation and that moreover can be made
relatively inexpensively. Alternatively a need exists at least to provide
the public with a useful choice. It is to the provision of a method and
apparatus that meets these and other needs that the present disclosure is
primarily directed.

SUMMARY

[0005] Briefly described, a method of deboning animal thighs is disclosed
for separating and collecting meat from thigh bones and an apparatus is
disclosed for performing the method. The method in one embodiment
includes or comprises grasping a thigh bone of an animal thigh at a hip
knuckle with a bone holder; cutting tissue near the hip knuckle; and
engaging the thigh bone adjacent the bone holder with a meat stripper.
The method further includes moving the bone holder and meat stripper away
from one another in a direction substantially coextensive with the
longitudinal extent of the thigh bone; allowing the meat stripper to pass
over the knee knuckle; and collecting the meat separated from the bone.
The method may further include, and the apparatus may perform the process
step of, cutting tissue adjacent a knee knuckle of the thigh bone prior
to allowing the meat stripper to pass over the knee knuckle.

[0006] The apparatus includes or comprises a plurality of processing
stations for carrying out the individual steps of the method, and the
processing stations are arranged along a path of conveyance defined by a
conveyor chain moving through a predefined path. The method and
apparatus, in one embodiment, enables the animal thighs to be hung from
their hip knuckles, rather than suspending the entire leg from an ankle
knuckle or the thigh from its knee knuckle as has been common in the
past. It has been found that stripping the meat from a thigh bone gives
the best yield when stripping from the hip knuckle in the direction of
the knee knuckle. Also, the cutting of knee knuckle related tissue prior
to stripping the meat off the bone improves the yield and the quality of
the meat. Further, with the method of this disclosure, the sleeve of meat
is not turned inside-out when it slides past the last knuckle to which it
is still attached before it is cut lose, as is the case with the prior
art methods and apparatuses.

[0007] The aspects as covered by the appended claims as well as other
aspects, features and advantages of the invention will be explained
further in the detailed description presented below in conjunction with
the accompanying drawing figures, which are briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a bird's eye perspective view of an apparatus according
for performing the method of the invention that embodies principles of
the invention in one preferred form;

[0009] FIG. 2 is a bird's eye perspective view of the apparatus of FIG. 1
from a second perspective.

[0010]FIG. 3 is a perspective view of a bone holder for use with the
apparatus of this disclosure.

[0012] FIG. 5 is a schematic top plan view of the apparatus of FIGS. 1 and
2.

[0013]FIG. 6 is a partial side elevation of a first tissue cutting
section of the apparatus of FIGS. 1 and 2.

[0014] FIG. 7 is a detailed elevational view of the first tissue cutting
section of FIG. 6 viewed from another perspective.

[0015] FIG. 8 is a bottom plan view of the cutting section of FIGS. 6 and
7.

[0016] FIG. 9 is a partial side elevation of a second tissue cutting
section of the apparatus of FIGS. 1 and 2.

[0017] FIG. 10 is a perspective view of a first cutting station for use in
the second tissue cutting section of FIG. 9.

[0018] FIG. 11 is a second cutting station for use in the second tissue
cutting section of FIG. 9.

[0019] FIG. 12 is a third cutting station for use in the second tissue
cutting section of FIG. 9.

[0020] FIG. 13 is a partial side elevation of a meat stripping and
discharge section of the apparatus of FIGS. 1 and 2.

[0021] FIG. 14 is a perspective view of a meat stripper unit for use in
the meat stripping and discharge section of FIG. 13.

[0022] FIG. 15 is a side elevation of an alternative embodiment of a bone
holder according to the disclosure.

[0023] FIG. 16 is a perspective exploded view of the alternative
embodiment of the bone holder of FIG. 15.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0024] Reference will now be made in detail to the drawing figures,
wherein like reference numerals may indicate like parts throughout the
several views. In FIGS. 1 and 2, bird's eye perspective views are shown
of opposite sides of one embodiment of an apparatus 1 for performing the
method of the invention. The apparatus 1 has an overhead conveyor that is
defined by a first linear conveyor section 3, a first carousel 5, a
second linear conveyor section 7, and a second carousel 9. The overhead
conveyor includes a conveyor chain (not shown but conventional) that is
arranged for movement in the direction of arrows 11 (FIG. 1) and 13 (FIG.
2). The conveyor chain is driven for movement by the second carousel 9,
which is provided for this purpose with an electric drive motor 15 that
may drive the carousel 9 through a gear reduction transmission. The first
carousel 5 is mounted for idle rotation and is driven indirectly by the
conveyor chain, as is conventional for such overhead conveying systems
for moving article hangers, such as bone holder 17, through and along a
processing path. All the basic elements described thus far are mounted on
and supported by a frame, generally indicated with reference numeral 19,
which can be supported by legs 21 (only shown in FIG. 1) to be at a
convenient height. In the direction of movement of the conveyor, the
apparatus 1, in accordance with the direction of movement of arrows 11
and 13, can be distinguished by or can define a loading section 23 (FIG.
2), a first tissue cutting section 25, a second tissue cutting section 27
and a meat stripping and discharge section 29.

[0025] As seen in FIG. 2, at the loading section 23, the bone holder 17
(only one of which is shown for clarity) is presented with a bifurcated
receiving end opening to the exterior of the apparatus 1 and exposed to a
worker at the loading station. The bone holder 17 is illustrated in more
detail in FIGS. 3 and 4, to which reference is made for a more detailed
description of the bone holder. While only one bone holder 17 is shown in
FIGS. 1 and 2, for clarity, it is to be understood that a plurality of
such bone holders are present and spaced at regular intervals along the
overhead conveyor. Such arrangements of items along the conveyor chain
are conventional and require no further explanation.

[0026] The bone holder 17, shown in more detail in FIG. 3, comprises a
bifurcated receiving end 31, which defines a receiving slot 33 for
receiving and supporting the hip knuckle (caput femoris) of a thigh bone
(femur), with the knee knuckle (condylus) hanging substantially
vertically downwardly below the receiving slot 33. The receiving end 31
of the bone holder 17 is rotatably received in a bone holder shackle 35
by a hollow central shaft, which is connected for rotation by a turning
gear 37. Also connected to the hollow central shaft for rotation of the
receiving end 31 is a gear pinion 39. Thus, rotation of the turning gear
37 or of the gear pinion 36 causes corresponding rotation of the
receiving end 31 about a substantially vertical axis.

[0027] An intermediate shackle 41 is pivotally connected to one end of the
shackle 35 and projects therefrom. The intermediate shackle is configured
to be pivotally connected to the bolt 43 of a successive like bone holder
17 such that plurality of interconnected shackles and intermediate
shackles form the conveyer chain. The bone holder also comprises a
swivelable or pivotable locking arm 45. This swivelable locking arm 45 is
mounted for swivelling or pivotal movement from an open position, as
shown in FIGS. 3 and 4, to a locking position, in which it engages in the
receiving slot 33 to prevent a thigh bone suspended in the receiving slot
33 from escaping. Swivelling of the locking arm 45 is effected through an
intermediate pinion 47 (FIG. 4), which is driven by a toothed rack or
pusher rod 49 that extends through the hollow central shaft of the bone
holder 17. Pusher rod 49 at its upper end carries a cam follower 51,
which in use is positioned to be engaged by a cam track of the apparatus
(not shown, but conventional). A compression spring 53 urges the pusher
rod 49 upwardly and thereby biases the locking arm to its open position
illustrated in FIGS. 3 and 4.

[0028] FIG. 5 schematically shows one example of the rotational movements
of the bone holder along the processing or conveying path through the
apparatus. The bone holders 17 are indicated by their turning gears 37,
and only a few bone holders are shown at the locations about the
conveying loop where their rotational positions or orientations may be
changed according to the disclosure. In the actual apparatus there can be
many more bone holders, but these are deleted in the schematic
representation of FIG. 5 for clarity. Schematically indicated by numeral
55 is a first turning station, which readjusts the orientations of bone
holders 17 returning from the second carousel 9 through 90° before
the bone holders enter the loading section 23. This positions the
receiving slots so that they face a loading platform 57, where an
operator may manually insert fowl or poultry thighs into the bifurcated
receiving ends 33 (FIG. 3) of the respective bone holders 17. The basic
concept of a turning station, such as turning station 55, is conventional
and well known in the art. To avoid unnecessary repetition, reference can
be had to the disclosure of European patent 0,786,208 for a further
description of such a turning station. Generally, such turning stations
use a predetermined number of protrusions that engage one or more of the
the diagonal slots at the corner points of the turning gear 37 of the
bone holders 17. Each such engagement rotates the turning gear 37 by
90° so that the gear and attached items can be selectively rotated
to a desired orientation.

[0029] Upon leaving the loading section 23, the bone holders 17 are turned
through 180° by a further, second turning station 59. Thereby the
receiving slots 33 (FIG. 3) are turned inwardly toward the interior of
the conveyor path before encountering the first carousel 5, where these
slots will be facing toward the axis of rotation of the first carousel.
Upon leaving the first carousel 5 and before entering the second tissue
cutting section 27, the bone holder 17 is again turned through 90°
in a counter clockwise direction in this example by a third turning
station 61. After this orientational adjustment, the receiving slot 33
(FIG. 3) is leading in or faces in the direction of movement (arrow 11).
Then, as the bone holder 17 moves through cutting section 27 the bone
holder 17 engages rotation station 63, in which its pinion gear 39
engages a toothed rack by which it is rotated through six full
revolutions of 360°, while at the same time being advanced by the
conveyer chain in the direction 11.

[0030] While at the loading section 23 (FIGS. 2 and 5), the bone holder
17, as mentioned above, is positioned to face with the open end of its
receiving slot 33 toward the loading platform 57. In this position an
animal thigh may be positioned by an operating person to be grasped by
the bifurcated receiving end 31 (see FIG. 3) at the thigh bone shaft
adjacent the hip knuckle (caput femoris). Preferably the animal thigh is
also positioned with the front part of the knee knuckle facing the
operator at the loading platform 57. Up to its transition past the first
carousel 5, the swivelable locking arm 45 remains in its open position
illustrated in FIG. 3. Upon leaving the first carousel 5, and in
association with the third turning station 61, the locking arm 45 is
moved into its locked position by urging the cam follower 51 downwardly
against the compressing the bias of spring 53 (FIG. 3). This can be
affected by an overhead cam track (not shown) positioned to engage and
urge downwardly the cam follower 51. By this movement the pusher rod 49
will swivel the locking arm 45 via the intermediate pinion 47 into its
locked position. The bone holder 17 will retain this locked configuration
up to its transition through the second carousel 9, and will be allowed
to open again by the cam track to release the thigh bone just prior to
passing again the first turning station 55 during a successive cycle.

[0031] Brief reference will now be made to FIG. 6, which shows the first
carousel that forms the first tissue cutting section 25 in a partial side
elevation looking from the side of the apparatus 1 where the loading
section 23 is located. For clarity, the cutting mechanisms have been
deleted from FIG. 6. The first carousel 5 is rotatably suspended from the
machine frame 19. The linear conveyer section 3 joins the first carousel
5 in a radial or tangential direction, so that each bone holder (not
shown in FIG. 6) becomes associated with a relevant one of a plurality of
pivotable knee end supports 65. The knee end supports 65 rotate with the
first carousel 5 and are each provided with a guide roller 67 for
controlling the pivotal position of the knee end support as will be
explained in more detail below.

[0032] FIG. 7 is a partial view, opposite from the direction of FIG. 6, of
a detail of the first carousel, but now showing the cutting mechanisms,
comprising a circular rotating cutting blade 68 in position relative to
the first carousel 5 and the knee end supports 65. Rotating cutting blade
68 is rotated by an electric motor unit 69. The rotating cutting blade 68
is confronted by a further circular cutting blade 71 that is mounted for
idle rotation on, in this case, the electric motor unit 69. The entire
electric motor unit 69 with its rotatable cutting blades 68, 71 is height
adjustably mounted on the machine frame 19 by a screw adjustment device
73. The pivotable knee end supports 65 assists in positioning the
individual knee ends of the animal thighs for passage between the opposed
circular cutting blades 68, 71. The knee end supports 65, by moving the
knees of the animal thighs radially outwardly with respect to the first
carousel 5, also ensure, by spreading out the thighs, that there is
sufficient spacing between successive knee portions, even when the thighs
are suspended from a narrow pitch conveyor chain where the thighs are
spaced closer together. A narrow pitch conveyor chain may be used to
reduce the floor space required for the machine and/or to increase its
throughput.

[0033] In FIG. 8 an arrangement is shown for pivoting the individual knee
supports 65 in respect of the cutting means. FIG. 8 is a view of the
first carousel 5 as seen vertically upward from below. In this view it is
possible to recognize a stationary excenter 75 that urges the guide
rollers 67, and thereby the pivotable knee end supports, outwardly to a
predetermined position with respect to the cutting blades 68, 71 on the
motor unit 69. The predetermined position is such that the front and back
portion of the bone shaft directly adjacent to the knee knuckle passes
between the cutting blades 68, 71 for cutting tissue that connects the
meat to the bone at that location. Thereby, such tissue is severed
adjacent the front and back of the knee knuckle end of the thigh bone.

[0034] From the first carousel 5, the bone holders 17 advance along the
overhead conveyor to the second linear section 7, after being turned by
the third turning station 61 anti-clockwise in this example through
90°. This turning movement positions each receiving slot 33 with
its opening facing in the direction of conveyance. Further, as explained
above, the locking arm 45 will now also have moved into its closed
position in which it is engaged in the receiving slot 33 of the
bifurcated receiving end 31. In this position and with the locking arm 45
closed, the bone holders 17 progress through the second tissue cutting
section 27.

[0035] A close-up detail of the second tissue cutting section 27 is shown
in FIG. 9. For a description of the second tissue cutting section 27,
reference can also be had again to FIG. 1. While progressing through the
second tissue cutting section 27 in the direction of arrow 11, an animal
thigh suspended from one of the bone holders 17 successively passes a
first cutting station 77, a second cutting station 79 and a third cutting
station 81. The first cutting station 77, as shown in more detail in FIG.
10, includes first and second parallel knife blades 83, 85. Each of the
first and second knife blades 83, 85 is mounted on a supporting frame 87
that is mounted to the machine frame 19 by means of a mounting flange 89.
The first and second knife blades 83, 85 are each pivotally linked to one
of a first and second pair of substantially parallel pivoting arms 91, 93
and 95, 97 respectively. Of each pair of arms 91, 93, respectively 95,
97, at least a first one 91, 95 is provided with a torsion spring 99 that
biases the knife edges 83A, 85A toward the centre of the path of
conveyance, which passes between the knife edges.

[0036] The first cutting station 77 is positioned at a level with respect
to the second linear conveyor section 7 to engage tissue adjacent the
knee knuckle of an animal thigh passing between the opposite knife edges
83A, 85A. Because the animal thigh has been rotated through 90° as
described, the knife edges 83A, 85A engage tissue that connects the meat
to the bone at opposite side portions of the bone shaft adjacent the knee
knuckle. This part of the tissue generally has not yet been severed by
the first tissue cutting section 25.

[0037] It is further seen in FIG. 9 that the first cutting station 77 is
also associated with a rotation cutting blade 101, driven by motor unit
103. The rotating cutting blade 101 is positioned below the parallel
knife blades 83, 85 at a level to remove any excess matter below the knee
knuckle, such as parts of the lower leg (tibiotarsus) that may have
resulted from imperfections in previous poultry or fowl processing
operations for obtaining the animal thighs. The frame 87 of the first
cutting station 77 is provided with a large cut-out through which the
rotating cutting blade 101 and part of the motor unit 103 may extend.
Preferably height adjustment is additionally provided to fine tune the
operation of the machine and the positions of the blades.

[0038] In FIG. 11 the second cutting station 79 is shown in more detail.
The second cutting 79 is positioned at a level with respect to the second
linear conveyor section 7 to engage tissue near the hip knuckle of an
animal thigh. To this end, the second cutting station 79 has opposite
first and second rotatable knife blades 105, 107, which are not driven.
The non-driven knife blades 105, 107 can be either stationary or idle to
rotate upon engagement with animal tissue. However, when mounted for idle
rotation, the rotation of the knife blades 105, 107 is preferably
provided with a certain amount of drag, so as not to compromise the
cutting action of the blade edges. The first and second rotatable knife
blades 105, 107 are each pivotally mounted from a supporting frame 109
that has a mounting plate 111 for attachment to the machine frame 19.
Both first and second rotary knife blades 105, 107 are biased and through
the path of conveyance through which the animal thighs are advanced so
that the blades overlap and interfere with the path of conveyance. Each
of the first and second rotary knifes 105, 107 is mounted from a
respective first or second swivel arm 113, 115, each carried on shafts
rotatable in bearing blocks 117, 118. Biasing of the rotatable knife
blades 105, 107 to overlap at the centre of the path of conveyance is
obtained by respective first and second torsion springs 120, 122 that
urge the arms 113, 115, and thus the blades, inwardly.

[0039] In FIG. 12 the third cutting station 81 is shown in more detail.
The third cutting station 81 includes a supporting frame 117 cantilevered
from a mounting plate 119 for attachment to the machine frame 19.
Supported by the support frame 117 are a first pair of opposing knife
blades 121, 123 and a second pair of opposing knife blades 125, 127.
Confronting knife edges 121A, 123A and 125A, 127A of each first and
second pair of opposing knife blades are biased towards the path of
conveyance, which passes between the blades, by torsion springs 129, 131,
133, 135, acting on at least one of respective arms 137, 139, 141, 143 of
the pairs of pivoting arms. The respective pairs each have a relevant
further arm 145, 147, 149, 151 that is mounted for idle rotation about a
vertically extending axis. With the arrangement of each knife blade being
pivotally connected to a pair of substantially parallel pivoting arms,
the knife blades each remain generally parallel to the path of
conveyance, but still have some freedom to deviate from the parallel
orientation when the hip bone of an animal thigh passes between the knife
blades. The knife edges 121A, 123A, 125A, 127A of the first and second
parts of opposing knife blades are positioned with respect to the second
linear conveyer section 7 at a level to engage tissue near the hip
knuckle that connects the meat of an animal thigh to the bone shaft.

[0040] When entering the first pair of opposing knife blades 121, 123 in
the direction of the arrow 11, the animal thigh is rotated about an axis
substantially coextensive with the longitudinal extent of the thigh bone
shaft between its opposite end protuberances formed by the hip and knee
knuckles. This rotation is induced by the bone holder 17 being rotated by
rotation station 63 (FIG. 5), which includes a toothed rack engaging gear
pinion 39 (not shown, but conventional). While passing through the first
and second pairs of opposing knife edges 121A, 123A, 125A, 127A,
juxtaposed in a downstream direction, the animal thigh is rotated through
six full revolutions of 360° to ensure that all or substantially
all tissue connecting the meat to the hip bone adjacent the hip knuckle
is severed. It should be clear to the skilled artisan that other
arrangements of the third cutting station are also possible. One such
possibility is the use of only a single pair of opposing knife edges,
which then would each have a longer length. Other variations may be
sought in the number of revolutions through which the bone holder 17 is
rotated while the bone is between the knife blades. Nonetheless, good
results have been achieved with the example as described, especially in
combination with a more compact narrow pitch conveyor system, using an
eight inch, rather than the more common twelve inch pitch, between the
suspended animal thighs.

[0041] In FIG. 13, a partial side elevation is shown of the meat stripping
and discharge section 29 (FIG. 1). The meat stripping and discharge
section 29 includes the second carousel 9 that receives the bone holders
17 from the second linear conveyer section 7 after these have been
advanced through the second tissue cutting section 27. The second
carousel 9 is driven by the electric drive motor 15 and rotates together
with cage 155. The cage 155 can turn around a stationary cam drum 157
which is provided with a cam track 159. The rotating cage 155 includes a
plurality of pairs of bars 161, 163 allowing vertical movement there
along of meat stripper units 165. The meat stripper units 165 function to
remove the meat from the bone, as detailed below.

[0042] The meat stripper units will now be further explained in reference
to FIGS. 13 and 14. From FIG. 14 it will be apparent that the meat
stripper unit 165 has a sliding block 167, with a pair of vertically
extending bores 169 (only one of which is visible in FIG. 14), for
accommodating the pair of bars 161, 163 of the rotating cage 155 in
sliding relationship. At the rear of sliding block 167 there is provided
a guide roller 171 that in use engages within the cam track 159 of the
stationary cam drum 157. At the front of the sliding block 167 are
positioned a first pivotable gripper arm 173 and a second gripper arm
175. The first and second gripper arms engage one another through gear
toothed segments 173A, 175A and gripper plates 173B and 175B are disposed
at the ends gripper arms 173 and 175 respectively. Accordingly, pivoting
movement of the gripper arms 173, 175 and respective gripper plates 173B,
175B is synchronised to move away from the closed position shown in FIG.
14 by equal amounts relative to a center line. The gripper plates 173B,
175B are yieldably urged toward the closed position by a pull spring 177.

[0043] The second gripper arm 175 has an arm extension 179 that carries a
cam follower wheel 181 at its distal end. The cam follower wheel 181 is
positioned to engage perimeter cam track sections 183, 185 that extend
about the rotating cage 155 as shown in FIG. 13. The cam track sections
183, 185 are stationary with respect to the rotating cage 155. A first
one of the cam track sections 183 is positioned to urge the gripper
plates 173B, 175B to the open position to engage a thigh hanging from an
adjacent bone holder 17 at the thigh bone directly below the bifurcated
end 31 of the bone holder 17. At a downstream end of the one cam track
section 183, the cam track 159 of the stationary cam drum 157 moves the
meat stripper unit 165, with the gripper plates 173B, 175B closed around
the bone shaft, in a vertically downward direction, by means of the guide
roller 171. During this downward movement and the meat stripper unit's
progress in the second carousel, the other of the cam track sections 185
will engage the cam follower roller 181 with an upwardly directed hump
185A and thereby slightly open the gripper plates 173B, 175B to pass over
the knee knuckle of the thigh bone.

[0044] Because the tissue holding the meat to the knuckle region of the
thigh bone has already been severed sufficiently as described above, the
continued downward movement of the meat stripper unit 165 substantially
completely removes the meat from the thigh bone. This removed meat may
then be collected by gravity in a collecting tray or alternatively by a
collecting conveyer placed underneath the second carousel 9 of the meat
stripper and discharge section 29. After removal of the meat, the bone
holders 17 continue their movement around the second carousel 9 and the
locking arm 45 is allowed to open again for release of the thigh bone
from which the meat has been removed. Suitable means may additionally be
provided to collect the discharged thigh bones, such as trays or
conveyors.

[0045] An alternative form of bone holder 17A is shown in FIG. 15 in side
elevation, whereas FIG. 16 is a perspective exploded view of the same
alternative form of bone holder. Because the upper portion of the bone
holder 17A is largely similar to that described in reference to FIGS. 3
and 4, the same reference numerals have been used to denote the bone
holder shackle 35, the turning gear 37, the gear pinion 39, the
intermediate shackle 41, and the connecting bolts 43.

[0046] Depending from a pinion shaft 201, which extends through the bone
holder shackle 35, is a receiving block 203, to which is mounted a
bifurcated receiving end 205. The bifurcated receiving end 205 has a
receiving slot 207, for receiving the hip joint protrusion of an animal
thigh hip bone (femur). Pivotally mounted to the receiving block 203 is a
swivelable locking arm 209 that pivots about a first pivot pin 211. The
swivelable locking arm 209 is biased to an open position by a torsion
spring (not shown, but conventional). In FIG. 15 the swivelable locking
arm 209 is shown in its closed position, which closed position is held by
a pivotable latch arm 213 mounted from a second pivot pin 215. The latch
arm 213 has a downwardly extending detent 217 that in FIG. 15 is shown
engaging an aperture 221 in a latch gripper 219. The latch gripper 219
can be adjustably attached to the locking arm 209, thereby to determine
the position of closure of the locking arm 209 and take into account
variations in bone shaft thicknesses.

[0047] Closing of the locking arm 209 is affected by a cam track means
(not shown, but conventional) acting directly on the locking arm, upon
passing and engaging the cam track means. In contrast to the bone holder
of FIGS. 3 and 4, the bone holder 17A of FIGS. 15 and 16 locks itself in
the closed position, so that it is not necessary to keep it engaged by a
cam track for as long as the locking arm 209 needs to be closed.
Conversely only a further short cam track or camming mechanism is needed
to unlatch the locking arm 209 to cause the latch arm 213 to lift the
detent 217 from the latch gripper 219 and thereby allow the locking arm
209 to swivel to its open position to which it is normally biased. The
latch arm can be actuated by a cam track that is positioned to depress
the exposed end of the latch arm 213 and cause it to pivot about the
second pivot pin 215. This arrangement has the benefit of reducing
friction and wear in the operation of the apparatus, by avoiding cam
track followers (such as 51 of bone holder 17), to be in prolonged
engagement with a cam track. The modified bone holder 17A, also results
in a reduction of raw materials, such as stainless steel, necessary in
the construction of a deboning apparatus.

[0048] Accordingly a method of mechanically deboning animal thighs for
separating and collecting meat therefrom is disclosed, as well as an
apparatus for performing this method, that includes automated individual
processing steps. The processing steps include grasping a thigh bone of
an animal thigh at a hip knuckle with a bone holder; cutting tissue near
the hip knuckle; and engaging the thigh bone adjacent the bone holder
with a meat stripper. Further the processing steps include moving the
bone holder and meat stripper away from one another in a direction
substantially coextensive with the longitudinal extent of the thigh bone;
allowing the meat stripper to pass over the knee knuckle; and collecting
the meat separated from the bone. In particular the method includes and
the apparatus performs the process step of cutting tissue adjacent a knee
knuckle of the thigh bone prior to allowing the meat stripper to pass
over the knee knuckle. The apparatus includes a plurality of processing
stations for carrying out the individual steps, and the processing
stations are arranged along a path of conveyance defined by a conveyor
chain moving through a predefined path that is defined by a first linear
conveyor section, a first carousel (5), a second linear conveyor section
(7), and a second carousel (9).

[0049] It is thus believed that the operation and construction of the
present invention will be apparent from the foregoing description. To the
skilled person in this field of the art it will be clear that the
invention is not limited to the embodiment represented and described
here, but that within the framework of the appended claims a large number
of variants are possible. Also kinematic inversions are considered
inherently disclosed and are considered to be within the scope of the
present invention. The terms comprising and including when used in this
description or the appended claims should not be construed in an
exclusive or exhaustive sense but rather in an inclusive sense. While the
invention has been illustrated within the context of preferred
embodiments and methodologies considered by the inventors to represent
the best mode of carrying out the invention, it will be clear that a wide
variety of additions, deletions, and modifications, both subtle and
gross, might be made to the illustrated embodiments without departing
from the spirit and scope of the invention delineated by the claims.
Features that are not specifically or explicitly described or claimed may
be additionally included in the structure according to the present
invention without deviating from its scope.